There is an increasing awareness among consumers of the problems presented by microbes, such as fungi, viruses, bacteria, protozoa, parasites, and the like. The news media broadcasts a steady stream of reports documenting a variety of health problems associated with microbes—from microbes impacting food supplies and fungus infesting building ventilation systems to mold contaminating homes and schools. Environmental officials have even gone so far as to call mold “the crisis of the decade” as federal and local governments are creating legislation designed to set mold exposure limits. As a consequence, though sales of antimicrobial products continue to grow rapidly, demand for such products continues to outpace supply.
There are a number of known techniques for delivering an antimicrobial agent. An “antimicrobial agent” refers to any compound or element that can kill or inhibit the growth of a microbe or other undesired organism, such as a mite. Examples of delivery techniques are discussed in U.S. Pat. Nos. 5,556,669; 4,938,958; 4,938,955; and 4,906,464, each of which is incorporated herein by this reference, and in Surfaces, Vol. 1, Issue 1. Such examples include antimicrobial coatings on household articles, such as cooking utensils, switch plates, and heating coils, HVAC components such as duct work, metal articles, such as steel, and carpet fibers.
A limitation of conventional systems is an unacceptably low likelihood that a microbe will come into contact with the antimicrobial agent, particularly in the case of contact microbes. It has been discovered that the surface area of the antimicrobial-containing surface is directly dependent upon the efficacy of the antimicrobial agent in killing microbes. However, existing antimicrobial-containing surfaces, including carpet fibers containing antimicrobial agents, generally have a relatively low surface area and therefore limited efficacy and low kill rates.